JP3290508B2 - Damping plate and damping structure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vibration damping plate and a vibration damping structure for reducing vibration.

[0002]

2. Description of the Related Art FIG. 1 shows a conventional vibration damping steel plate 1.
A layer of an elastomer 4 such as a synthetic resin or a synthetic rubber is provided between the two steel plates 2 and 3.

[0003]

In recent years, engines have tended to have higher horsepower and higher revolutions, and this tendency has led to an increase in combustion pressure and an increase in heat load. At the same time, in recent years, engines have tended to be lightweight, and this tendency has led to a decrease in the rigidity of the cylinder head and the cylinder block. As a result, structural deformation due to combustion pressure in the cylinder head and cylinder block increases, and concomitantly the relatively stiff rocker cover, oil pan cover, and heat insulator (heat shield) mounted on the engine. Vibration also increases, which has been found to be a major factor in engine noise generation. 2 shows an example of a rocker cover (5 is a rocker cover, 6 is a rocker cover gasket), FIG. 3 shows an example of an oil pan cover, and FIG. 4 shows an example of a heat insulator.

[0004] In response to the recent tightening of noise regulations for reducing engine noise, various measures against noise in the rocker cover and the like have been studied. It has already been found that it is extremely effective for reduction and has already been actually implemented. However, when the above-mentioned conventional damping steel sheet 1 is used, the following various drawbacks have occurred.

(A) When the thermal load on the engine increases,
Naturally, the temperature of the lubricating oil and the temperature of the exhaust gas rise, and as a result, the temperature of the rocker cover, the oil pan cover and the like and the thermal load of the insulator and the like increase. In such a case, since the heat resistance of the elastomer 4 filled between the steel plates 2 and 3 is low (about 120 ° C.), the noise reduction effect is reduced. In particular, when the temperature exceeds 60 ° C., the noise reduction effect tends to be significantly reduced.

(B) Rocker covers, oil pan covers, insulators, etc. are mounted by tightening bolts with gaskets interposed. However, when the thermal load increases, the heat resistance of the internal elastomer 4 is poor. , And softens with the temperature rise, the withstand pressure decreases, and the internal elastomer 4 flows laterally in a high surface pressure portion such as a bolt tightening portion.
Often, the steel sheet 2 or 3 protrudes outside.

(C) Since the torque of the tightening bolt increases with the protrusion of the elastomer 4 described in the preceding paragraph, the axial force of the bolt decreases, and oil leakage from the gasket mounting portion easily occurs.

(D) In the process of producing a rocker cover, an oil pan cover, a heat insulator, etc.,
Although drawing work is required to squeeze the flat vibration-damping steel sheet 1, the elastomer 4 between the steel sheets 2 and 3 tends to flow laterally during this drawing work. For this reason, when drawing is performed by the upper and lower dies, the steel sheets 2 and 3 are not tightly held, wrinkles often occur, deep drawing is restricted, and workability is poor.

(E) When the layer of the elastomer 4 is thickened,
As the lateral flow increases further, drawing becomes impossible due to the elasticity of the elastomer 4 (ie,
Even if the convex portion of the mold presses the damping steel sheet 1, the elastomer 4
Is not absorbed by the deformation of the steel plates 2 and 3).

[0010] The present invention has been made in view of such circumstances, and even if the thermal load increases, the noise reduction effect does not decrease, and the elastomer does not protrude in a high surface pressure portion such as a bolt tightening portion. It is another object of the present invention to provide a vibration damping plate and a vibration damping structure having good workability.

[0011]

According to the present invention, there is provided a vibration damping plate comprising:
Thickness 3 containing compressible fiber, elastomer and filler
No. 00 coated with a layer of compound
On the surface of the one metal plate on the side of the compound layer, a second metal
It is formed by stacking plates .

The vibration damping structure according to the present invention has a thickness of 300 μm or less containing compressible fibers, an elastomer and a filler.
A second metal plate is laminated on the surface of the first metal plate coated with the lower compound layer, on the side of the compound layer, without bonding.

As the compressible fiber, a compressible inorganic fiber or a compressible organic fiber may be used alone, or a mixture of both may be used.

Examples of the compressible inorganic fiber include glass fiber, ceramic fiber, rock wool, mineral wool, fused quartz fiber, chemically treated high silica fiber, fused alumina silicate fiber, continuous alumina fiber, stabilized zirconia fiber, and boron nitride fiber. And alkali titanate fibers, whiskers, boron fibers, carbon fibers, metal fibers, and the like.

Examples of the compressible organic fibers include aromatic polyamide fibers, polyamide fibers, polyolefin fibers, polyester fibers, polyacrylonitrile fibers, polyvinyl alcohol fibers, polyvinyl chloride fibers, and polyurea fibers. And polyurethane-based fibers, polyfluorocarbon-based fibers, phenol fibers, and cellulosic fibers.

Further, as the elastomer, for example, NB
R, styrene butadiene rubber (SBR), isoprene rubber (IR), chloroprene rubber (CR), butadiene rubber (BR), butyl rubber (IIR), ethylene-propylene rubber (EPM), fluoro rubber (FPM), silicone rubber (SI) ), Chlorosulfonated polyethylene (C
SM), ethylene vinyl acetate rubber (EVA), polyethylene chloride (CPE), butyl chloride rubber (CIR), shrimp chlorohydrin rubber (ECO), nitrile isoprene rubber (N
IR), natural rubber (NR) and the like, and an oil-extended rubber obtained by adding a naphthenic process oil to a rubber material such as the SBR can also be used.

As the filler, an inorganic filler is preferable, and for example, clay, talc, barium sulfate, sodium bicarbonate, graphite, lead sulfate, tripoliite, wollastonite and the like can be used.

The amount of the compressible fiber and the filler in the compound is preferably 50% or more (weight). The thickness of the compound layer is preferably about 0.05 mm to 0.3 mm.

[0019]

In the vibration-damping plate and the vibration-damping structure of the present invention, a layer of a compound containing a compressible fiber, an elastomer and a filler is provided between metal plates, not a layer of an elastomer alone such as synthetic resin or synthetic rubber. , Heat resistance is improved (heat-resistant temperature can be about 400 ° C.).
Therefore, even if the thermal load increases, the noise reduction effect does not decrease.

Further, since there is no lateral flow of the compound layer, the compound does not stick out from between the metal plates in a high surface pressure portion such as a bolt tightening portion.

Further, as described above, since the compound does not protrude, the torque holding force of the tightening bolt is good, and the torque of the tightening bolt is small, so that the rocker cover or the damper structure according to the present invention provides a rocker cover, When an oil pan cover, a heat insulator, or the like is configured, resistance to oil leakage from a gasket attached to these components increases.

Further, since the lateral flow of the compound layer is extremely small, the phenomenon of relaxation of the pressing force at the time of drawing is small. Therefore, there is no occurrence of wrinkles at the time of deep drawing and the workability is good.

Further, as described above, since the lateral flow of the compound layer and the phenomenon of stress relaxation during processing are small, the thickness of the compound layer can be increased to about 300 μm.

In the vibration damping structure of the present invention, the first metal plate and the second metal plate can be integrated by, for example, an outer peripheral clinch, and the second metal plate and the compound layer can be integrated. Because it is not bonded, even if there is a difference in elongation between the first metal plate and the second metal plate during drawing, the compound layer between these metal plates does not "clog", Further, workability is improved.

Further, since the second metal plate and the compound layer are not bonded to each other, an air layer is formed between the compound layer and the second metal plate, so that the vibration damping effect and the noise reduction effect are further improved.

[0026]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the embodiments shown in the drawings. Example 1 A compound having the following composition was prepared.

(A) 30% by weight of glass fiber (b) 10% by weight of fibrillated aromatic polyamide fiber (Kepler pulp, manufactured by DuPont) (c) 16% by weight of nitrile rubber (NBR) (d) Rubber chemical 4% by weight (e) Inorganic filler 40% by weight As rubber chemicals, vulcanizing agents such as sulfur, zinc oxide, magnesium oxide, peroxide, dinitroribenzene, and thiazole-based compounds, polyamine-based compounds, sulfonated Vulcanization accelerators such as phenamide-based compounds, dithiocarbamate-based compounds, aldehydeamine-based compounds, guanidine-based compounds, thiourea-based compounds, and xanthate-based compounds can be used.

As shown in FIG. 5, a compound 1 having the above-described composition is formed on one surface of a first metal plate 12 made of SPCC steel sheet having a heat-resistant adhesive 11 applied on one surface in advance.
A second metal plate 15 made of SPCC steel plate coated on one side with a heat-resistant adhesive 14 on the surface of the layer of the compound 13 on the side opposite to the first metal plate 12; The adhesive layer 14 is superposed on the 13 layers, and the layers are adhered while heating and pressing. 140-1 after bonding
The vibration damping plate 16 was manufactured by performing a heat treatment in a 60 ° C. temperature atmosphere for 40 to 60 minutes. The heat treatment is performed to promote a cross-linking reaction of the rubber, the rubber chemicals and the heat-resistant adhesives 11, 14, and the like. The thickness of the first metal plate 12 and the second metal plate 15 is 0.3 mm, the thickness of the layers of the heat-resistant adhesives 11 and 14 is 0.01 mm, and the thickness of the layer of the compound 13 is 0.2 mm. Has been respectively.

In the vibration damping plate 16 thus obtained, not the layer of the elastomer alone but the layer of the compound 13 containing the compressible fiber, the elastomer and the filler is interposed between the metal plates 12 and 15. Therefore, the heat resistance is improved, and the noise reduction effect does not decrease even if the thermal load increases. FIG.
FIG. 4 is a characteristic diagram showing a change in vibration damping performance of a conventional vibration damping steel plate and a vibration damping plate 16 of the present embodiment with temperature. Here, the magnitude of the damping performance of the damping plate is represented by a loss coefficient η defined by the following equation.

[0030] η = ΔE / 2πE = (1 / π) · l n (A n / A n + 1) However, E: energy of the vibration Delta] E: energy A _n of vibration is lost in one cycle: n-th cycle of the amplitude A _{n + 1} : amplitude in the (n + 1) th cycle In FIG. 7, the ordinate represents the loss coefficient η, and the abscissa represents the temperature.

As is apparent from FIG. 7, the vibration damping performance of the present embodiment and the conventional vibration damping steel sheet are the same up to about 60 ° C., but a significant difference in the vibration damping characteristics is seen above 60 ° C. In this embodiment, even when the temperature increases, the vibration damping performance does not decrease.

Further, in the vibration damping plate 16, since the layer 13 of the compound 13 is unlikely to laterally flow and peel off, the compound 13 sticks out between the metal plates 12 and 15 in a high surface pressure portion such as a bolted portion. There is no.

Further, since the compound 13 does not protrude as described above, the torque holding force of the tightening bolt is good, and
When the rocker cover, the oil pan cover, the heat insulator, and the like are formed by the damping plate 16 because the torque reduction of the tightening bolt is small, the resistance against oil leakage from the gasket attached to these components increases.

Further, since the lateral flow of the layer of the compound 13 is extremely small, the phenomenon of relaxing the pressing force at the time of drawing is small, and therefore the rate of wrinkles at the time of drawing is small and the workability is good.

Further, as described above, since the lateral flow of the layer of the compound 13 and the stress relaxation phenomenon during processing are small, the thickness of the layer of the compound 13 can be increased to about 300 μm.

Since the vibration damping plate 16 has the above-mentioned excellent functions, if the rocker cover, the oil pan cover and the heat insulator are manufactured using the vibration damping plate 16, the above-mentioned conventional problems can be solved. can do. Of course, the damping plate 16 can be used for something other than the rocker cover and the like. [Embodiment 2] FIG. 6 shows an embodiment of a vibration damping structure according to the present invention. In this case, a layer of the same compound 13 as the compound 13 in the first embodiment is coated on one surface of the first metal plate 12 made of the SPCC steel sheet having one surface coated with the heat-resistant adhesive 11 in advance,
A second metal plate 15 made of SPCC steel sheet is laminated on the surface on the compound 13 side without bonding. The first metal plate 12 and the second metal plate 15 are integrated by folding the outer periphery 15 a of the second metal plate 15 and clinching the first metal plate 12.

In this damping structure, the damping plate 16
And the second metal plate 15 and the layer of the compound 13 are not bonded to each other, so that the first metal plate 12 and the second metal plate 15 are stretched during drawing. Even if there is a difference, the compound 13 layer between the metal plates 12 and 15 does not "leave", so that the workability is further improved.

Further, the second metal plate 15 and the compound 1
Since the third layer is not bonded, an air layer is formed between the layer of the compound 13 and the second metal plate 15, so that the vibration damping effect and the noise reduction effect are further improved.

Such a vibration damping structure also has a rocker cover,
It can be applied to oil pan covers and heat insulators, and also to other types.

In each of the above embodiments, the SPCC steel plate is used as the first and second metal plates. However, in the present invention, the first and second metal plates are other steel plates, and other than the steel plate. Metal plate, for example, an aluminum plate, a stainless steel plate or the like can also be used.

[0041]

As described above, the vibration-damping plate and the vibration-damping structure according to the present invention do not reduce the noise reduction effect even when the thermal load increases, and the elastomer in the high surface pressure portion such as the bolted portion. Excellent effects such as no protrusion and good workability can be obtained.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a conventional damping steel sheet.

FIG. 2 is a perspective view showing an example of a rocker cover of the internal combustion engine.

FIG. 3 is a perspective view showing an example of an oil pan cover of the internal combustion engine.

FIG. 4 is a perspective view showing an example of a heat insulator of the internal combustion engine.

FIG. 5 is a sectional view showing one embodiment (embodiment 1) of the vibration damping plate according to the present invention.

FIG. 6 shows an embodiment of a vibration damping structure according to the present invention (Embodiment 2).
FIG.

FIG. 7 is a characteristic diagram showing a change in damping performance of a conventional damping steel plate and the damping plate of the first embodiment with temperature.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Heat resistant adhesive 12 First metal plate 13 Compound 14 Heat resistant adhesive 15 Second metal plate 16 Damping plate

Claims (4)

(57) [Claims] Claims: 1. A compressible fiber, an elastomer and a filler.
The layer of the compound having a thickness of 300μ or less
Surface of the compounded metal layer on the side of the compound layer
And a second metal plate laminated thereon . 2. A first metal plate having a heat-resistant adhesive applied to one side thereof in advance and having a thickness of 300 μm or less containing a compressible fiber, an elastomer and a filler is provided on the surface of the first metal plate on the adhesive side. > A layer of a compound layer, and a surface of the second metal plate coated with a heat-resistant adhesive on one surface is bonded to a surface of the compound layer opposite to the surface of the first metal plate. Damping board. 3. A second metal plate is bonded to a surface of the first metal plate coated with a layer of a compound having a thickness of 300 μm or less containing a compressible fiber, an elastomer, and a filler on the compound layer side. Vibration damping structure that is laminated without using. 4. An outer periphery of the second metal plate is folded back and
By clinching the first metal plate,
The metal plate and the second metal plate are integrated with each other.
Damping structure.